EBay question any ideas?

[♥♫i♥bloo♫]

That means there was an error on the address. Since you are sure the paypal address on file is correct, I would message the seller to see if they wrote the address wrong on the package.
The package will be sent back to the seller in this case and the seller has to ship it to you again. You may want to check if the post office has it, but most likely, it is already going back to the sender.